This is a proposal for the Mentored Clinical Research Award (K23) to provide supervised experience in clinical research. The didactic portion of this grant will center on the Master's of Clinical Research and Biostatistics program at Virginia Commonwealth University. These courses are designed to teach: design, conduct, analysis, interpretation, reporting and dissemination of clinical research. The electives will include epidemiology and evaluation of racial differences in disease. A wide variety of conferences and seminars will also be utilized. Dr. Domenic Sica will be the primary mentor for this award. Clinical researchers in endocrinology, biostatistics, clinical pharmacology and quality health care will assist with the protocol and education. The protocol has been developed both to answer scientific questions as well as to help gain experience with techniques necessary to pursue clinical research in areas of hypertension and renal failure. The primary goal of the protocol is to evaluate change in nocturnal decline in blood pressure (dipping status) following potassium supplementation and to correlate these changes with renal functional reserve (ability of creatinine clearance to increase following a protein load). In a randomized blinded parallel placebo controlled protocol, subjects determined to be consistently non-dippers or dippers on ambulatory blood pressure monitoring will be randomized to receive either placebo or KCl 60 mEq/day for 8 weeks. Dipping status and renal functional reserve will be measured at baseline and following placebo or KCl. Endothelin-1 levels, urinary electrolyte and catecholamine excretion will be measured during each study period. The primary hypothesis is that decreased nocturnal decline in blood pressure (non-dippers) will correlate with decreased renal functional reserve at baseline and that these abnormalities will be normalized by KCl supplementation. Dipping status and renal functional reserve will remain stable in the placebo treated non-dippers and the dippers. The subjects for this study will be young normotensive African Americans, a population at high risk for the development of hypertension and renal failure. Finding modifiable risk factors prior to the onset of clinical hypertension and renal failure is key to developing future preventive programs to decrease the incidence and prevalence of hypertension and renal failure. The ultimate career goal is to improve my clinical research skills to allow me to be an active productive clinical researcher while meeting the other demands of an academic medicine career. Research projects will focus on developing methods to decrease the incidence and prevalence of renal failure and hypertension by intervening prior to the onset of irreversible vascular damage. Improving treatment and outcomes in patients with renal failure are also of interest.